Lawn mower starter system

ABSTRACT

A lawn mower includes an internal combustion engine, a rotary tool driven by the internal combustion engine, an electric motor coupled to the internal combustion engine and configured to start the internal combustion engine, a receiving port mounted to the internal combustion engine, an energy storage device configured to be selectively inserted into and removed from the receiving port without tools, a first user interface, and a second user interface, wherein the electric motor starts the internal combustion engine upon actuation of the first user interface and the second user interface.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This is a continuation of application Ser. No. 13/289,613, filed Nov. 4, 2011, which is incorporated herein by reference in its entirety.

BACKGROUND

The present invention generally relates to internal combustion engines and outdoor power equipment powered by such engines, such as lawn mowers, snow throwers, portable generators, etc. More specifically, the present invention relates to a starter system and energy storage system for an engine.

Outdoor power equipment may use an internal combustion engine to drive a tool of the equipment, such as a rotary blade of a lawn mower or an axial cam pump of a pressure washer. Typically the outdoor power equipment includes a brake mechanism that selectively prevents or stops rotation of the tool. The brake may stop a flywheel of the engine, correspondingly stopping the crankshaft and rotating tool coupled to the power takeoff of the crankshaft.

Starting the braked outdoor power equipment may be cumbersome, requiring release of the brake followed by activation of the engine. For lawn mowers and other types of outdoor power equipment, release of the brake may include rotating a bail to draw an inner-wire of a Bowden cable that lifts the brake mechanism. Then, activation of the engine typically further includes manually pulling a recoil starter rope or activating an electric starter for the engine. A need exists for a less-cumbersome and faster process to start the outdoor power equipment.

Furthermore, the outdoor power equipment may include the engine mounted to a frame or a base plate. If an electric starter is included, the starter motor is typically connected to an interface on the handle of the outdoor power equipment so that the operator may activate the starter motor while standing in an operational position, such as behind the handle. During assembly of the outdoor power, a power source, control circuitry, and wiring associated with the starter motor are coupled to the handle, the frame, and the engine, the attachment of which may be a time-consuming and labor-intensive process. A need exists for an engine having a starter motor that facilitates efficient assembly of the outdoor power equipment.

SUMMARY

One embodiment of the invention relates to a lawn mower including an internal combustion engine, a rotary tool driven by the internal combustion engine, an electric motor coupled to the internal combustion engine and configured to start the internal combustion engine, a receiving port mounted to the internal combustion engine, an energy storage device configured to be selectively inserted into and removed from the receiving port without tools, a first user interface, and a second user interface, wherein the electric motor starts the internal combustion engine upon actuation of the first user interface and the second user interface.

Another embodiment of the invention relates to a lawn mower including an internal combustion engine, an electric motor configured to start the internal combustion engine, a rotary tool driven by the internal combustion engine, a brake mechanism for inhibiting rotation at least one of the implement and the internal combustion engine, a release mechanism allowing for selective releasing of the brake mechanism, a lock-out device configured to selectively prevent release of the brake mechanism, and an interface configured to permit an operator to release the lock-out device, wherein the electric motor starts the internal combustion engine upon actuation of the interface and the release mechanism.

Another embodiment of the invention relates to a lawn mower including a four-stroke air-cooled internal combustion engine including a vertical crankshaft, a rotary tool driven by the crankshaft, a first air intake for providing combustion air to the internal combustion engine, a second air intake for providing cooling air for cooling the internal combustion engine, an electric motor coupled to the internal combustion engine and configured to start the internal combustion engine, a control circuit controlling operation of the electric motor, a receptacle mounted to the internal combustion engine, the receptacle electrically coupled to the electric motor, and a battery removably attached to the receptacle, wherein energy from the battery is provided to the electric motor to start the internal combustion engine.

Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims.

BRIEF DESCRIPTION OF THE FIGURES

The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, in which:

FIG. 1 is a perspective view of a lawn mower according to an exemplary embodiment of the invention.

FIG. 2 is a perspective view of a handle for outdoor power equipment according to an exemplary embodiment of the invention.

FIG. 3 is a perspective view of a handle for outdoor power equipment according to another exemplary embodiment of the invention.

FIG. 4 is a schematic diagram of a starter system for an engine according to an exemplary embodiment of the invention.

FIG. 5 is a perspective view of components of a starter system for outdoor power equipment according to an exemplary embodiment of the invention.

FIG. 6 is a perspective view of an engine assembly according to an exemplary embodiment of the invention.

FIG. 7 is a perspective view of a battery charging station according to an exemplary embodiment of the invention

FIG. 8 is a perspective view of a battery being coupled to an engine according to an exemplary embodiment of the invention.

FIG. 9 is a perspective view of a starter for the engine assembly of FIG. 6 according to an exemplary embodiment of the invention.

FIG. 10 is a circuit diagram of a controller for a starter of an engine according to an exemplary embodiment of the invention.

FIG. 11 is a circuit diagram of a controller for a starter of an engine according to another exemplary embodiment of the invention.

FIG. 12 is a perspective view of a pressure washer according to an exemplary embodiment of the invention.

DETAILED DESCRIPTION

Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the present application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting.

Referring to FIG. 1, outdoor power equipment, in the form of a lawn mower 110, includes an internal combustion engine 112 coupled to a rotary tool, such as the blade in a deck 114 of the lawn mower 110, an auger, a saw, tines, a drill, a pump, or other rotary tools. In some embodiments, the lawn mower 110 further includes wheels 116 and a rearward extending handle 118 designed to be pushed by an operator walking behind the lawn mower 110. In other contemplated embodiments, the outdoor power equipment may be in the form of a rotary tiller, a pressure washer, a snow thrower, a lawn tractor or riding mower, an edger, a portable generator, or other equipment, with a corresponding powered tool, such as tines, a pump, an auger and impeller, an alternator, a drive train, or other tools.

Still referring to FIG. 1, the lawn mower 110 includes a starter system. According to an exemplary embodiment, the starter system includes an electric motor 120 that is selectively coupled to the engine 112 such that the electric motor 120 is configured to rotate the crankshaft of the engine 112 to start the engine 112, and is then configured to disengage once the engine 112 is running. In some embodiments, the motor 120 is fastened to the engine 112, such as being mounted on top of or to a side of the engine 112. Gearing (e.g., gear reduction, transmission) may extend between the motor 120 and the crankshaft of the engine 112, or the motor 120 may be connected directly to the crankshaft of the engine 112.

According to an exemplary embodiment, an operator may engage the starter system via the handle 118 of the lawn mower 110. In some embodiments, the handle 118 includes a lever 122, button, toggle, or other interface that the operator may use to command the starter system to start the engine 112. In some embodiments, the command is relayed from the handle 118 via a linkage 124, such as an electric wire transmitting an electrical signal, a Bowden cable communicating a mechanical signal, or another type of linkage. In contemplated embodiments, a transmitter and start button are coupled to the handle (e.g., clipped on, integrally mounted with), and the starter system includes an integrated receiver configured to receive commands wirelessly provided by the transmitter to start the engine. According to an exemplary embodiment, the command from the operator is received directly or indirectly by the motor 120, and the motor 120 rotates the crankshaft to start the engine 112.

In some embodiments, the starter system is integrated with a bail 126 of the lawn mower 110. A brake mechanism (e.g., friction brake, ignition interrupt switch or circuit, etc.) may be holding the blade or other tool, locking the crankshaft of the engine 112, or otherwise preventing operation of the power equipment. When the operator actuates the bail 126 to release the brake mechanism from rotating members (e.g., blade, crankshaft, power takeoff, flywheel) of the lawn mower 110, the action simultaneously actuates the motor 120 to start the engine 112. As such, releasing of the brake mechanism synergistically also starts the engine 112, easing operation of the lawn mower 110 or other outdoor power equipment by reducing the steps necessary for activation.

In some embodiments, the lawn mower 110 includes an interlock 128 (e.g., lock-out device, signal interrupt) to prevent release of the brake and engagement of the motor 120. According to an exemplary embodiment, the operator must release the interlock 128 before the bail 126 can be operated to engage the motor 120 to start the engine 112. Different types of mechanical and electrical interlocks may be used in varying contemplated embodiments to prevent inadvertent release of the brake and starting of the engine, such as when a user moves the power equipment into or out of a garage or storage shed by grabbing the handle, or if the bail is unintentionally bumped. Furthermore, engagement of the interlock 128, in some embodiments, is also configured to prevent inadvertent release of the brake when the handle 118 is being folded over the deck 114 to put the lawn mower 110 in a storage configuration.

In some embodiments, the interlock 128 may prevent a signal from being sent via the linkage 124 to engage the motor 120 and release the brake. The interlock 128 may physically disconnect the linkage 124 from the bail 126, such as by removing a linking pin that joins the bail 126 to the linkage 124, removing a clamp that holds the linkage 124 to the bail 126, or otherwise physically separating the bail 126 and linkage 124. Release of the interlock 128 then physically or electrically connects the bail 126 (or other brake release) to the controller 132 (e.g., control system, control circuit, computerized controller) such that operation of the bail 126 is communicated to the controller 132 to simultaneously start the engine 112.

In other embodiments, the interlock 128 physically prevents (e.g., blocks, holds, jams) rotation of the bail 126 when the interlock 128 is engaged. In some such embodiments, a cam may be rotated into or out of the path of the bail 126, optionally preventing rotation of the bail 126. In other such embodiments, a clamp of the interlock 128 may bind the bail 126 to the handle 118, preventing rotation of the bail 126 until released. In still other such embodiments, a sleeve or latch may slide over the bail 126, holding the bail at a fixed angle until released. The mechanical interlock described in this paragraph may be used in an embodiment where no electrical wiring harness on the handle 118 is required to support the starting of the electric motor 120 and engine 112.

In contemplated embodiments, an electrical signal may indicate to the controller 132 that the interlock 128 has been released, such as a signal communicated via the linkage 124, via radio frequency communication, hardwired, or otherwise. The signal is provided in addition to a separate signal associated with movement of the bail 126. Without the signal indicating release of the interlock, the signal associated with movement of the bail will not be sufficient to instruct the controller to start the engine. The electrical signal may be associated with a pass code, a key, a scanned finger print, or other access-limiting device.

According to an exemplary embodiment, the lever 122 (e.g., interface, release mechanism, trigger) may serve to release the interlock 128, allowing operation of the bail 126 to release the brake and to start the motor 120. In some embodiments, pulling of the lever 122 may move a physical obstacle out of the rotational path of the bail 126. In other embodiments, pulling of the lever 122 may mechanically or electrically connect the bail 126 and the linkage 126. Other mechanisms, such as buttons, switches, toggles, dials, etc., may serve as release mechanisms to release the interlock 128. In some embodiments, conventional mechanical rotational interlocks or electrical switches (e.g., signal disconnects) are used as the interlock.

In general, integration of the starter system with a handle of outdoor power equipment allows the operator to start the engine from the rear of the outdoor power equipment, such as several feet from the powered tool of the outdoor power equipment (e.g., snow thrower auger, lawn mower blades). Further, the integration supports an electric starting system for a walk behind mower that can be engaged by a user without actuation of a key or push-button. In other embodiments, the starter system may include a start button or other interface to engage the starter system that is located on the engine or elsewhere. For example, in contemplated embodiments, such an interface may include a smart phone application or remote control that wirelessly provides a start command or authorization code to a receiver coupled to the outdoor power equipment.

According to an exemplary embodiment, the starter system further includes an energy storage device 130 (e.g., electrical storage device) and a controller 132. The energy storage device 130 may include one or more batteries, capacitors, or other devices. When the operator engages the starter system, the linkage 124 communicates the command to start the engine directly or indirectly to the controller 132, which electrically connects the energy storage device 130 to power the motor 120. In some embodiments, the controller 132 is coupled to a governor of the engine 112 (see, e.g., speed sensor 420 as shown in FIG. 4), and disengages the motor 120 (e.g., cuts power to the motor 120, high-side switching of the battery power source, low-side switching of the ground side of the circuit) when the engine 112 is running at a sufficient speed.

In some embodiments, the motor 120, the energy storage device 130, and the controller 132 are fastened directly to the engine 112, which may be configured for efficient assembly of outdoor power equipment using the engine 112. As such, the starter system in some embodiments may come fully assembled with the engine 112 and ready for connection to a linkage configured to provide a signal from the handle (e.g., linkage 124). In some embodiments, an interface (e.g., start button, toggle, switch) for starting the engine is positioned on the engine itself, and no additional connections are necessary—the manufacturer need only attach the engine to the deck or corresponding feature and attach the tool to the power takeoff of the engine. In any such case, considerable time and effort may be saved during the manufacturing process and a potential source of manufacturing difficulty may be removed (i.e., that associated with the fastening and electrical connection of the components of the starter system during assembly of the outdoor power equipment). In still other embodiments, some or all of the starter assembly may be fastened to the deck of a lawn mower or corresponding feature of other power equipment.

Referring to FIGS. 2-3, handles 210, 310 for outdoor power equipment, such as a lawn mower, rotary tiller, snow thrower, etc., each include a bail 212, 312 and an interlock 214, 314 with a release button 216, 316. In contemplate embodiments, the release button 216, 316 may release the bail 212, 312 from being interlocked by allowing the bail 212, 312 to move, or by coupling the bail 212, 312 and linkage 124. In FIG. 2, the release button 216 is to the side of the bail 212, while in FIG. 3, the release button 316 for the interlock 314 is on top of the bail 312. The release button 216 of FIG. 2 may disengage a member from blocking movement of the bail, while the release button 316 may connect the bail 312 and linkage 124. In other contemplated embodiments, release buttons or other release mechanisms may be positioned elsewhere on the handle, the engine, or on another component of the outdoor power equipment.

Still referring to FIGS. 2-3, in other contemplated embodiments, the buttons 216, 316 may be used to provide a signal directly or indirectly to a motor to start an engine, without regard to the bail 212, 312. However, integrating the buttons 216, 316 with the bail 212, 312 allows for a two-step process to start the engine (i.e., release interlock and operate bail), while synergistically using the operation of the bail 212, 312 to both release the brake as well as to engage the starter. In still other embodiments, other forms of interlocks and release mechanisms for the interlocks may be used, such as a biased lever (see lever 122 of interlock 128 as shown in FIG. 1), latch, thumb-print reader, etc.

In some embodiments, a three-step process is used to engage the power equipment, such as first disabling or releasing an interlock; second presenting a key, a code, or other device to release an access-control mechanism (e.g., lock out, lock); and third pulling the bail. In alternate embodiments, the key hole or interface for the access-control mechanism may be positioned on the handle or on the engine.

Referring to FIG. 4, outdoor power equipment 410 (shown schematically) includes an engine 412 and a powered tool 414 (e.g., rotary blade) driven by the engine 412. In some embodiments, a motor 416 is coupled to the engine 412, and the powered tool 414 is coupled to a power takeoff 418 of the engine 412. A speed sensor 420 (e.g., governor) may be coupled to the engine 412 to regulate the speed of the engine 412. Also, a brake 422 may be coupled to a rotary member of the outdoor power equipment 410, such as the flywheel of the engine, the power takeoff 418 of the engine, etc., to stop the engine as well as the associated powered tool.

In some embodiments, the outdoor power equipment 410 includes a handle 424 having a release mechanism 426, where the release mechanism 426 is configured to allow a user to release the brake 422 from the handle 424. The release mechanism 426 may allow a user to release the brake 422 by engaging the bail (or other element) with a linkage connected to the brake 422, or by disengaging an element blocking movement of the bail. The handle 424 may be coupled to the engine 412 and tool 414 directly, or via an intermediary member (e.g., deck 114 as shown in FIG. 1). The engine 412 may further include a battery 428 for powering the motor 416 and a control system 430 for operating the motor 416.

According to an exemplary embodiment, the control system 430 is configured to receive inputs associated with the release mechanism 426. In some embodiments, when the release mechanism 426 is actuated to release the brake 422, the release mechanism 426 triggers a switch 432, which provides to the control system 430 a signal that is indicative of the release of the brake 422. The signal may be provided via a mechanical linkage, wirelessly, a hardwired electrical connection, or otherwise. In some embodiments, the control system 430 then actuates the motor 416 to start the engine 412 or uses the information in control logic configured to start the engine as a function of the status of the brake and other factors. As such, operation of the release mechanism 426 may simultaneously provide a start signal to the control system 430 as well as release the brake 422. No additional operations to start the engine 412 may be required.

According to an exemplary embodiment, the control system 430 is configured to receive additional inputs from the speed sensor 420 or another component of the engine 412 (e.g., ignition circuit). The speed sensor 420 or other component provides the control system 430 with information associated with the speed of the engine 412. When the engine 412 is running at a sufficient speed, the control system 430 then disengages the motor 416 (e.g., turns off, disconnects, cuts power to, etc.).

In contemplated embodiments, the control system 430 associated with the start system may receive additional or different inputs used to control starting of the engine, such input from a sensor configured to indicate whether the outdoor power equipment has moved recently. Movement of an axle or wheels of such outdoor power equipment may trigger a sensor that provides a signal to the control system. The signal, in combination with an electric timer providing time-related context for the movement, may serve as an additional indicator that the operator intends to activate the engine. In contemplated embodiments, the control system 430 includes a timer and is configured to deactivate the motor if the engine has not started within a predetermined amount of time. In some contemplated embodiments, the control system 430 includes a temperature sensor and is configured to prime the engine with an automated primer pump or adjust the choke or throttle plate if ambient temperature is above or below a predetermined temperature, if a portion of the engine is above or below a predetermined temperature, or if the difference between ambient and engine temperature is above or below a predetermined amount. In contemplated embodiments, the control system 430 may also provide a signal output to the operator, such as a visible indicator on a display coupled to the handle or engine, or an audible alert. In some such embodiments, the signal output may include as an error message, a low-fuel message, a replace-oil message, or another such message.

Referring to FIG. 5, components of a system 510 include a brake cable 512 (e.g., Bowden cable) and a brake pad 514 for an associated engine of outdoor power equipment. According to an exemplary embodiment, the brake cable 512 is configured to be coupled to the bail of a handle of outdoor power equipment (see, e.g., bails 126, 212, and 312 as shown in FIGS. 1-3). When an operator activates the bail, the brake cable 512 moves a pivot 516 coupled to the brake pad 514. The brake pad 514 then releases, allowing the engine associated with the system 510 to drive a powered tool of the outdoor power equipment.

According to an exemplary embodiment, the engine associated with the system 510 further includes a starter system including a switch 518, an electronic control 520, a battery 522, and an electric starter motor 524. When the operator activates the bail to lift the brake pad 514, the pivot 516 simultaneously activates the switch 518. The switch 518 then provides a signal to the electronic control 520 that the brake pad 514 has been lifted and that the electronic control 520 may start the engine associated with the system 510 with the electric starter 524. The electronic control 520 then connects the electric starter 524 to the battery 522. The switch 518 may be a switch already associated with the brake, but used to provide signals to both an actuator of the brake and the starter system (e.g., ignition ground), or the switch 518 may be an additional switch solely used for the starter system.

Still referring to FIG. 5, the electronic control 520 includes hard-wired circuitry and is configured to receive additional inputs from the engine associated with the system 510. In some embodiments, the additional inputs include an indication of the speed of the engine associated with the system 510 from a governor or other component of the engine (e.g., electrical pulses from the ignition system). The additional inputs may include a current state of the engine associated with the system 510, such as whether the engine associated with the system 510 is running, etc. The starter system is also coupled to a ground 526.

Referring to FIGS. 6-9, an engine 610 includes an exhaust 612, a fuel tank 614, an engine cover 616, an air intake 618 for combustion processes, an air intake 620 for cooling the engine, and a starter system having an energy storage device, such as a battery 622, a capacitor, multiple batteries or capacitors, or another energy storage device. Applicants note that the engine 610 of FIGS. 6-9 mirrors the engine 112 of FIG. 1, and both are single-cylinder, four-stroke cycle, vertically-shafted, small engines. Other engine types and designs may be used, such as engines that are horizontally-shafted, two- or more cylindered, diesel powered, cold-weather structured, etc.

Although shown as proximate to the fuel tank 614 and exhaust 612 in FIGS. 6 and 8-9, the energy storage device may be positioned elsewhere on the exterior and/or in an internal port of the engine 610. In some embodiments, where the energy storage device is sensitive to high temperature, it may be preferred to position the energy storage device away from the exhaust 612, which may become hot during operation of the engine 610.

According to an exemplary embodiment, the energy storage device is configured to power a starter motor (see, e.g., motor 120 as shown in FIG. 1) integrated with the engine 610. In some embodiments, the energy storage device may be further configured to power other systems of the engine 610, such as an engine control unit (ECU) having control circuitry coupled to sensors or detectors integrated with the engine (e.g., brake release, fuel-level detector, ignition-fouling detector, governor, etc.).

According to an exemplary embodiment, the energy storage device is the battery 622, which is rechargeable. As shown in FIG. 7, the battery 622 may be charged at a charging station 624 or may include a charging port integrated with the battery (e.g., battery pack with charging port to receive a connection from a wire coupled to an outlet or the charging station). The battery 622, in other embodiments, may alternatively plug directly into a wall outlet, or the charging station may be wall mounted or plug directly into a wall outlet.

In some embodiments, the energy storage device is or includes a bank of capacitors, where the capacitors are configured to charge and release electrical energy in a relatively short (e.g., less than 10 seconds), high-powered output. In some such embodiments, some of the capacitors of the bank are coupled with one another in groups (e.g., series or parallel), and the groups are configured to output sequentially in time with respect to one another. Accordingly, the capacitors are specifically configured to be able to power the motor to start the engine 610 without much additional energy storage capacity so as to be relatively compact in size and inexpensive. Use of capacitors may also allow for faster charging when compared to batteries, such as faster charging on the charging station 624 (FIG. 7).

In contemplated embodiments, the starter motor is configured to draw power from the engine 610, such as during periods of lesser loads on the engine. The starter motor is then driven by the engine 610 to provide an electric output. The electric output may then be routed by the ECU or otherwise to the charge the energy storage device. Such a system may be particularly useful for an engine driving an alternator of a portable generator, where the alternator may temporarily be powered by the energy storage device to start the engine and then, once the engine has started, the alternator may be used to recharge the energy storage device.

Referring to FIG. 8, the battery is configured to be inserted (e.g., dropped, lowered, placed) into a receiving port 626 integrated with the engine. Integrating the receiving port with the engine reduces the assembly burdens for manufacturing outdoor power equipment, as disclosed above. However in contemplated embodiments, the receiving port may not be integrated with the engine. For example, FIG. 7 shows a charging station 624 or charging port, which may be similar to such a port on a deck of the engine.

In some embodiments, the battery 622 has a cross section forming an isosceles trapezoid, triangle, diamond, or other wedge shape, or shape having a narrower lower portion 628 relative to an upper portion 630 in contact with the receiving port 626. The receiving port 626 is contoured (e.g., V-shaped, U-shaped, etc.) to receive the battery 622, which may be guided into position by interfacing with the contours of the receiving port 626 and gravity.

In some embodiments, the battery 622 includes slots or grips 632 for lifting and holding the battery 622. A locking mechanism, such as a hook or latch may snap into place when the battery 622 is inserted into the receiving port 626 and hold the battery 622 in the receiving port 626. Pinching the grips 632 together may release the locking mechanism to allow removal of the battery 622 from the receiving port 626.

According to an exemplary embodiment, the starter system further includes a switch 636 (e.g., toggle, lever, key) that is integrated with the battery 622, the receiving port 626, or elsewhere on the engine 610. As shown in FIGS. 8-9, the switch 636 may rotate from an off position (FIG. 8), where the battery 622 is not electrically connected to components of the engine 610 (e.g., starter motor, ECU), to an on position (FIG. 9), where the battery 622 is electrically connected to the components. In other embodiments, rotation of the switch 636 also or alternatively engages the locking mechanism to hold the battery 622 in the receiving port 626. In various contemplated embodiments, the switch 636 may be configured to interrupt electrical connectivity of the battery, the control circuit, or both.

According to an exemplary embodiment, the starter system includes an interface, such as a button 634 on the receiving port 626. The button 634 faces outward and is accessible when the battery 622 is seated in the receiving port 626. In some embodiments, the interface allows the operator to start the engine via the starter system. In other embodiments, the interface may be used to initiate charging of the battery or another function.

According to an exemplary embodiment, the electrical control circuits shown in FIGS. 10-11 are each configured provide hard-wired logic for a starter system according to the disclosure provided herein. In some embodiments, each circuit contains essentially all analog parts. In some embodiments, each circuit or another such circuit is configured to detect when the bail closes (or opens) a switch (see, e.g., switch 518 as shown in FIG. 5). In other embodiments, a circuit is configured to sense when the brake is pulled (see, e.g., brake pad 514 as shown in FIG. 5), and then to enable ignition of the engine. In other contemplated embodiments, a circuit may be further configured to sense vibration of the engine or Venturi vacuum strength in the carburetor, and cut power to the motor when the associated information indicates that the engine is running.

According to an exemplary embodiment, the circuits of FIGS. 10-11 are contained on circuit boards that are integrated with the engine (see, e.g., controller 132 as shown in FIG. 1), and may be fully powered by the battery or other on-board source. Accordingly, the circuits may require no electrical interface to components of the lawn mower or other outdoor power equipment aside from those carried by or integrated with the engine. No additional wiring or hook ups are required. Accordingly, the assembly process for the associated outdoor power equipment may be improved, as discussed above.

Referring now to FIG. 12, a pressure washer system 710 includes the engine 610 of FIG. 6. To start the engine 610, an operator may press the button 634 shown in FIGS. 8-9. In some such embodiments, braking of the system may occur via an ignition interrupt that prevents sparks from igniting fuel and air in a combustion chamber of the engine 610. Resistance provided by the water pump of the pressure washer system 710 then slows (i.e., brakes) the engine 610. In other contemplated embodiments, an engine of a portable generator may use a similar starter system and battery 622, as well as a similar braking system. Power provided by the generator may be used to charge the battery 622 of the starter system.

The construction and arrangements of the starter system for an engine, as shown in the various exemplary embodiments, are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. Some elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process, logical algorithm, or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present invention. 

What is claimed is:
 1. A lawn mower, comprising: an internal combustion engine; a rotary tool driven by the internal combustion engine; an electric motor coupled to the internal combustion engine and configured to start the internal combustion engine; a receiving port mounted to the internal combustion engine; an energy storage device configured to be selectively inserted into and removed from the receiving port without tools; a first user interface; and a second user interface; wherein the electric motor starts the internal combustion engine upon actuation of the first user interface and the second user interface.
 2. The lawn mower of claim 1, further comprising a locking mechanism for securing the energy storage device in the receiving port.
 3. The lawn mower of claim 2, wherein the energy storage device includes a movable grip for releasing the locking mechanism to allow removal of the energy storage device from the receiving port.
 4. The lawn mower of claim 2, wherein the energy storage device includes a pair of movable grips configured to be pinched together by a user to release the locking mechanism and allow removal of the energy storage device from the receiving port.
 5. The lawn mower of claim 1, wherein the first user interface comprises a bail and the second user interface comprises an electrical switch.
 6. The lawn mower of claim 5, wherein the electrical switch comprises a button.
 7. The lawn mower of claim 1, wherein the first user interface comprises a bail and the second user interface comprises a mechanical interlock.
 8. The lawn mower of claim 1, wherein the first user interface comprises a bail and the second user interface comprises an electrical interlock.
 9. The lawn mower of claim 1, wherein the energy storage device includes a charging port configured to receive a connection for charging the energy storage device.
 10. The lawn mower of claim 1, further comprising a charging station, wherein the energy storage device is configured to be selectively coupled to the charging station for charging the energy storage device.
 11. The lawn mower of claim 1, further comprising a switch for selectively electrically coupling the energy storage device to the electric motor, wherein in an off position of the switch, the energy storage device is not electrically coupled to the electric motor, and wherein in an on position of the switch, the energy storage device is electrically coupled to the electric motor.
 12. The lawn mower of claim 11, further comprising a locking mechanism for securing the energy storage device in the receiving port, wherein the locking mechanism is engaged when the switch is in the on position and disengaged when the switch is in the off position.
 13. A lawn mower, comprising: an internal combustion engine; an electric motor configured to start the internal combustion engine; a rotary tool driven by the internal combustion engine; a brake mechanism for inhibiting rotation of at least one of the implement and the internal combustion engine; a release mechanism allowing for selective releasing of the brake mechanism; a lock-out device configured to selectively prevent release of the brake mechanism; and an interface configured to permit an operator to release the lock-out device; wherein the electric motor starts the internal combustion engine upon actuation of the interface and the release mechanism.
 14. The lawn mower of claim 13, further comprising: a receiving port attached to the internal combustion engine; and an energy storage device configured to be selectively inserted into and removed from the receiving port without tools.
 15. The lawn mower of claim 13, further comprising a control system for operating the electric motor, wherein actuation of the interface and the release mechanism results in the transmission of a start signal to the control system to cause the electric motor to start the internal combustion engine.
 16. The lawn mower of claim 15, wherein the start signal is provided via a mechanical linkage.
 17. The lawn mower of claim 15, wherein the start signal is provided wirelessly.
 18. The lawn mower of claim 15, wherein the start signal is provided via an electrical connection.
 19. A lawn mower, comprising: a four-stroke air-cooled internal combustion engine including a vertical crankshaft; a rotary tool driven by the crankshaft; a first air intake for providing combustion air to the internal combustion engine; a second air intake for providing cooling air for cooling the internal combustion engine; an electric motor coupled to the internal combustion engine and configured to start the internal combustion engine; a control circuit controlling operation of the electric motor; a receptacle mounted to the internal combustion engine, the receptacle electrically coupled to the electric motor; and a battery removably attached to the receptacle, wherein energy from the battery is provided to the electric motor to start the internal combustion engine.
 20. The lawn mower of claim 19, wherein the battery is configured to be selectively inserted into and removed from the receptacle without tools. 